1. Field of the Invention.
The invention relates to a method for testing a workpiece by means of ultrasound in a curved area of its surface.
2. Background and Relevant Art.
In particular, workpieces produced from fiber composite materials such as glass-fiber reinforced or carbon-fiber reinforced plastics (GRP or CRP), can exhibit material faults due to the respective manufacturing method chosen, or following their deployment. In particular in the case of mechanically highly stressed and safety-relevant components, this is a major problem. Inspection of such materials is effected using non-destructive ultrasonic test techniques, in particular with a contact-free test, wherein an ultrasonic transducer generating an ultrasonic signal is not in direct contact with the workpiece. Rather, the ultrasound is coupled into the workpiece, for example via a fluid passageway. Contact-free test procedures have, among other things, the advantage that they have an optimum test coverage. But one disadvantage is that the ultrasonic transducer must be exactly positioned with respect to the workpiece in order to obtain a meaningful measurement or test result. But since the workpieces themselves, as well as the ultrasonic transducers or ultrasonic transducer arrangements that are used are subject to certain mechanical positioning inaccuracies, in particular for workpieces with areas with curved surfaces this can lead to measurements which do not provide a solid basis for drawing conclusions regarding the composition of the workpiece. A re-testing of the workpiece with corrected positions of the ultrasonic transducer relative to the workpiece must then be carried out.